I have had events like that from all kind of companies, nothing unique about this, and it's certainly not about boosting their numbers. It's about getting students to learn their technologies and then use them later.
Blackberry recently paid developers to port apps to their platform. Is that "artificially boosting their numbers", or just smart marketing? I don't see any problems with this.
When they literally don't care what the app is (paying a developer $100 for a flashlight app), yeah, it doesn't speak well of their desires to serve their users.
Similar experiences here. Our bog standard "write an Android application for an external client" had the strange requirement of "port to Windows 8 Phone" attached to it.
I went to a congress, last year, I think, and Microsoft and Nokia representatives came on stage to announce that for every Windows Phone app they got on the store (and they had an expedite process going on during the event), they'd gift a Nokia phone.
For many it wasn't clear it would be a Nokia Asha phone, but, still, they got a crapload of young students writing apps for them.
They just wanted to boost their numbers artificially, and they were willing to pay hundreds to students for making these crappy things.